1. Field of the Invention
The present invention relates to the manipulation of information by electronic data processing systems and in particular to electronic data processing systems that mark text strings for subsequent processing.
2. Description of the Related Art
Many data processing system applications provide for the manipulation of marked text by a person, called a user, who is using a data processing system. Specific text may be marked by the user in, for example, a program code listing or a word processing document. This marking of text may also be called clipping, highlighting, capturing, or blocking. Operations may be performed upon the marked text, such as clear, copy, cut, delete, move or paste. These operations may involve a clipboard.
A user may mark a string of text in various ways. In one method, the user may place a cursor or mouse pointer on a character at one end of the text string to be marked, enter a keyboard or mouse command, then move the cursor or pointer to the character at the other end of the text string to be marked and enter another keyboard or mouse command. The first and last characters of the text string may be called start and stop, or open and close, delimiters. The second keyboard or mouse command may optionally initiate an action to be performed upon the marked text string; thus, different second commands may, for example, delete the marked text string or begin a copy or move operation on the marked text string.
Another method of marking a text string includes the placement of the pointer or cursor on the first character of the text string to be, marked, entering a keyboard or mouse command to initiate the marking, and then entering a character, as by the keyboard; in response, the system marks the text string beginning at the cursor or pointer position and ending at the first occurrence of the character selected. Repeated entry of the same character or selection of a different character may expand the marking to the next occurrence of the newly selected character, which entry may also be repeated to further expand the marking. Expansion of the mark may be completed upon entry of a character or command that is incompatible with further expansion of the mark. In this method, the first keyboard or mouse command causes the system to accept the entry of subsequent keyboard characters as commands.
Another method allows the marking of text with a dedicated single command. The user first positions the cursor or pointer at the, first character of the text string to be marked, and then enters a dedicated single command that marks the text string from the pointer or cursor position to the end of a line, the end of a sentence, the end of a paragraph, the end of a page or some other predefined section, as specified by the dedicated single command entered by the user.
Dedicated single commands may be provided that not only mark text from the cursor or pointer position to a predefined end point, but also initiate or perform a predefined operation upon the marked text such a dedicated single command may, for example, delete all text from the location of the cursor or pointer to the end of the line. Other dedicated single commands may similarly delete all text from the cursor or pointer position to the end of the sentence, section, paragraph or page. Similar dedicated single commands may be provided to initiate other clipboard commands, such as move or copy, of the text from the cursor or pointer location to the end of the line, sentence, paragraph or page or other predefined section.
Other commands may be provided to mark or delete the entire sentence in which the cursor or pointer is positioned upon the entry of the single dedicated command. Such a command may mark or delete all text beginning with a capital letter located at or to the left of the cursor or pointer and ending with a punctuation mark located at or to the right of the cursor, such as a period or question mark, and including up to three space after the punctuation mark. Similar dedicated keyboard commands may provide for the deletion of the entire line, section, paragraph or page upon Which the cursor or pointer is located.
These predefined dedicated text string marking commands may eliminate the need to sequentially place the pointer or cursor at both the beginning and the end of the text string to be marked. However, only a limited range of predefined string commands may be provided, as each predefined string requires a separate, specific command. If the number of predefined commands is increased, the advantages of single command operation may be compromised by the need to present multiple menus or enter multiple keystrokes to accommodate the larger number of choices.
A method and apparatus are desired in which a single command may allow a user to mark text between predefined pairs of open and close delimiters and, further, in which the same single command may allow the user to mark text between different predefined pairs of open and close delimiters. A method and apparatus are also desired in which the second delimiter of a text string to be marked may be identified in response to the first delimiter, either as specified by the user or determined by the method or apparatus.